1. Field of the Invention
The invention relates to a tension absorbing means (tension absorber) produced from a flexible strand which is only loadable under tension. Such tension absorbing means are used in practice for bracing, holding, securing, tensioning, lifting, fastening and stowing goods and persons. The application of force usually occurs via two attachment points, between which the tension absorbing means is tensioned. In the case where the tension absorbing means of the type mentioned here is used for lifting goods, these are referred to as “sling gear” in the technical language.
2. Description of Related Art
Ropes, chains, straps, slings and suchlike can be used as tension absorbing means. Ropes and straps have the advantage that they can be produced cost-effectively as continuous products, from which the respective rope or strap can be cut to the length required. This is accompanied by the disadvantage that after having been cut to length the length of the ropes and straps can only be shortened by taking appropriate action, such as by forming knots or loops which can impair the functional reliability, or with the aid of additional components, such as hooks, eyelets and suchlike. Additional measures also have to be taken to store away the excess rope or strap length properly in each case. These measures are particularly laborious if the respective rope or strap has a certain inherent stiffness and correspondingly can only be wound or folded over large radiuses.
Chains, on the other hand, as a result of them being distinctly multi-jointed can be draped without any problems even in the most confined spaces if their chain links consist of inelastic material. Furthermore, the effective length of chains used as tension absorbing means can be easily adapted to the requirements imposed in practice by attaching a suitable attachment element, such as a hook or shackle, for example for coupling to the goods item to be respectively fastened, to that chain link whose distance from the one end of the chain corresponds to the distance between the attachment points to be joined together for fastening by means of the chain. The individual chain links can also be easily used to couple further tension absorbing means to the chain. A disadvantage of chains, however, is that their manufacture requires a lot of effort. This applies irrespective of which material they are produced from. Hence, the chain links always have to be prefabricated individually. In addition, at least every second chain link has to initially remain open, so that when the chain is put together it can be joined to the chain links between which it is arranged. After the chain has been put together, the previously open chain links have to be closed.
Highly stressed chains used as tension absorbing means are also nowadays usually produced from solid steel material. The chain links are generally produced by forging or bending. However, chains are also in use which are manufactured from a flexible strand material. In the case of such chains, the individual chain links are, for example, produced from textile or wire sections which are formed into rings. The advantages of chains over conventional ropes or straps used as tension absorbing means lie in the fact that they can be easily shortened and can also then be easily stored away if they are produced from materials which only have a slight bendability. Particularly if the chains consist of textile material their low weight and as a consequence their easy manageability add to their ability to be stored away easily. Furthermore, it has proved advantageous in practice that when chains consisting of textile material come into contact with other components the risk of damage is very much less than with chains consisting of steel or other hard materials. In addition, chains consisting of textile material are insensitive to moisture and therefore are suitable for fields of application, in which chains consisting of conventional steel would be exposed to a high level of corrosion.
However, these advantages are accompanied by the disadvantage also in the case of chains whose links are formed from strand material that these kind of chains can only be manufactured with a large amount of effort. Irrespective of which flexible material the strand consists of, from which the individual chain links are formed, the joining places where the individual links of the chain are in each case joined to form a ring prove to be the weak points which in practice would require regular inspection and could impair the load-bearing capacity of chains consisting of textile material.